1. Field of the Invention
The field of the invention relates to gas operated firearms. Gases flow from the firearm barrel into an operating piston which actuates an automatic mechanism for extraction, ejection, feeding and chambering of the ammunition. The improvement is in the means for regulating the flow of gases from the barrel to the operating piston.
2. Description of the Prior Art
Attempts have been made in the prior art to control the volume of the gases that flow into operating pistons which actuate automatic mechanisms for extracting, ejecting, feeding and chambering ammunition in firearms such as gas operated shotguns. These attempts involve the venting of surplus gases to the atmosphere and have met with success when firing shotgun shells having relatively low pressure. However, when heavier loads such as magnum shot shells are utilized, severe hardship on firearm mechanisms occurs and to alleviate this situation special model firearms are manufactured for the heavy magnum loads or special barrels are used which restrict the flow of gases by means of smaller gas orifices to the barrel. It is not practical to attempt to control the size and area of orifices in the barrel conveying gases to the actuating piston. The result is that it has been necessary to provide different interchangeable barrels having sizes or quantities of gas orifices. Typically in the prior art the gun is provided with a receiver with which the actuating cylinder has sliding engagement. The prior art lacks the improvements of the herein invention as to the metering or regulating of flow of gas to the operating piston.